A057423 Diagonally symmetric n-celled polyominoes with 1 hole.

1, 0, 5, 4, 20, 18, 79, 84, 304, 332, 1149, 1309, 4312, 5005, 16136, 19049, 60347, 71979, 225867, 271781, 846667, 1025315, 3179798, 3871607, 11966976, 14633947, 45131841, 55395495, 170560833, 210008554, 645861961, 797419730, 2450316125, 3032540599

Offset: 7

Author

N. J. A. Sloane, Sep 05 2000

Keywords

• nonn

Comments

The sequence refers to polyominoes with one hole and precisely one diagonal symmetry. - John Mason, Jan 16 2023

Links

• Tomás Oliveira e Silva, Enumeration of polyominoes

Crossrefs

Cf. A056881.

Extensions

a(29)-a(49) from John Mason, Jan 16 2023